According to existing technologies, a K-type cage bearing includes a cage and rolling elements located in the cage, which is mainly applied to gearboxes and automobile transmissions. The K-type cage bearing is usually mounted to a rod shaped element and encircled by a circular element. The inner circumferential surface of the circular element servers as one roller path of the rolling elements, and the outer circumferential surface of the rod shaped element encircled by the K-type cage bearing servers as another roller path of the rolling elements. The cage of existing K-type cage bearings has an opening along the circumferential direction. Before the bearing is mounted to the rod shaped element, the opening of the cage is kept to be open, thus the K-type cage bearing can be mounted to the rod shaped element along a radial direction of the rod shaped element. Thereafter, components disposed on two sides of the opening are engaged with each other.
Referring to FIG. 1 and FIG. 2, an existing K-type cage bearing is illustrated. The bearing has a cage which is mainly constituted by two co-axial lateral rings 1 and 2. A plurality of transverse bars 3 are set to connect the two lateral rings and spaced arranged along a circumferential direction of the cage. Among the plurality of traverse bars 3, those two located adjacent to the opening of the cage are respectively defined as a first transverse bar 31 and a second transverse bar 32.
The first transverse bar 31 is configured with two connection elements 4, and the second transverse bar 32 is also configured with two connection elements 4. The two connection elements 4 set on one common transverse bar are spaced and arranged along an axial direction of the cage. The two connection elements 4 on the first transverse bar 31 are adapted to match with the two connection elements 4 on the second transverse bar 32, respectively. Specifically, along the circumferential direction, a first connection element on the first transverse bar 31 faces to a first connection element on the second transverse bar 32; while a second connection element on the first transverse bar 31 faces to a second connection element on the second transverse bar 32. In other words, along the circumferential direction of the cage, the connection elements 4 on the first transverse bar 31 face to the connection elements 4 on the second transverse bar 32 in one to one manner. Referring to FIG. 3, each of the connection elements 4 includes: a plate-shaped body 41 having two plate surfaces facing to opposite directions along a radial direction of the cage; and a protruding part 42 located on one of the two plate surfaces of the plate-shaped body 41. Regarding two of the connection elements 4 which face to each other along the circumferential direction, the protruding part 42 of one connection element is set at the plate surface of the plate-shaped body 41 facing the inner side of the cage, and the protruding part 42 of the other connection element is set at the plate surface of the plate-shaped body 41 facing the outer side of the cage. Furthermore, the plate surfaces of these two connection elements 4 where the protruding parts 42 are located fit neatly with each other along the radial direction of the cage, and the two protruding parts 42 stand against each other along the axial direction, so as to close the opening of the cage. As such, the two connection elements 4, which are configured to face to each other along the circumferential direction, are adapted to limit each other from moving along the radial direction via the two plate-shaped bodies 41, and adapted to limit each other from moving along the axial direction via the two protruding parts 42. The broken line in FIG. 2 indicates the position of the protruding part which is sheltered by the plate-shaped body and thus can not be seen in FIG. 2.
However, existing cage bearings are unable to achieve pre-tightness along the circumferential direction. Specifically, regarding the two connection elements 4 which face to each other along the circumferential direction, their movements along the circumferential direction can not be limited. Thus, when the K-type cage bearing works and vibrates, the cage may get loose or even break along the circumferential direction at the joint of the connection elements, which will affect the normal working of the machine using the cage bearing.